body {
  background-color: #20202c;
  height: 100vh;
}

#container {
  height: 400px;
  left: calc(50% - 200px);
  position: absolute;
  top: calc(50% - 200px);
  width: 400px;
}
#container #sun {
  background-color: yellow;
  border-radius: 50%;
  -webkit-box-shadow: 0 0 30px white;
          box-shadow: 0 0 30px white;
  height: 100px;
  left: 150px;
  position: absolute;
  top: 150px;
  width: 100px;
}
#container .orbit {
  border: solid;
  border-color: white transparent transparent transparent;
  border-radius: 50%;
  border-width: 1px 1px 0 0;
  -webkit-box-sizing: border-box;
          box-sizing: border-box;
  position: absolute;
  -webkit-transform: rotate(0deg);
          transform: rotate(0deg);
  -webkit-transform-origin: center;
          transform-origin: center;
}
#container .orbit#earth-orbit {
  -webkit-animation: orbit 36.5s linear infinite;
          animation: orbit 36.5s linear infinite;
  height: 300px;
  left: 50px;
  top: 50px;
  width: 300px;
}
#container .orbit#moon-orbit {
  -webkit-animation: orbit 2.7s linear infinite;
          animation: orbit 2.7s linear infinite;
  height: 80px;
  left: -25px;
  top: -25px;
  width: 80px;
}
#container .orbit .globe {
  border-radius: 50%;
  position: absolute;
}
#container .orbit .globe#earth {
  background: aqua;
  height: 30px;
  right: 28px;
  top: 28px;
  width: 30px;
}
#container .orbit .globe#moon {
  background: #d6d6d6;
  height: 12px;
  right: 2px;
  top: 8px;
  width: 12px;
}

@-webkit-keyframes orbit {
  to {
    -webkit-transform: rotate(360deg);
            transform: rotate(360deg);
  }
}

@keyframes orbit {
  to {
    -webkit-transform: rotate(360deg);
            transform: rotate(360deg);
  }
}


html,body,ul{
	margin: 0;
	padding: 0;
}

ul,li{
	list-style: none;
}

/*将每个li标签转化成行元素  因为我们到时候是将这些照片并排来排列显示  */
ul li{
	display: inline;
}
/*再给ul设置一下宽度值和margin   margin四个值依次是上右下左 顺时针方向*/
ul{
	width: 970px;
	margin:0 0 18px 10px ;
}
/*然后可以设置图片宽度，在没设置之前图片是占满了全屏*/
ul img{
	display: block;/*转为块元素*/
	width: 190px;
	margin-bottom: 12px;
}
/*再接着给图片设置边框  注意我们这里是用a标签包裹了img图片  所以我们如果要对图片进行留白边操作的话就设置a标签*/
ul a{
	background-color: #FFFFFF;
	display: inline;/*转为行元素*/

	margin: 0 0 27px 30px;
	padding: 10px 10px 15px;/*上内边距是 10px; 右、左内边距是10px;下内边距是 15px*/
	text-decoration: none;
	font-size: 17px;
	color: #333333;
	/*这里设置的box-shadow四个值意思是：水平位移0;垂直位移3px;模糊半径6px;阴影颜色rgba(0,0,0,0.25)*/
	box-shadow: 0 3px 6px rgba(0,0,0,0.25) ;
	-webkit-box-shadow: 0 3px 6px rgba(0,0,0,0.25);
	-moz-box-shadow: 0 3px 6px rgba(0,0,0,0.25);
	-o-box-shadow: 0 3px 6px rgba(0,0,0,0.25);
	-ms-box-shadow: 0 3px 6px rgba(0,0,0,0.25);
}

ul li a:after{
	content: attr(title);
}

ul li:nth-child(even) a {
	-webkit-transform: rotate(2deg);
	-moz-transform: rotate(2deg);
	-ms-transform: rotate(2deg);
	transform: rotate(2deg);
}
ul li:nth-child(5n) a {
	-webkit-transform: rotate(5deg);
	-moz-transform: rotate(5deg);
	-ms-transform: rotate(5deg);
	transform: rotate(5deg);
	position: relative;
	right: 5px;
}
ul li:nth-child(8n) a {
	position: relative;
	top: 8px;
	right: 5px;
}
ul li:nth-child(11n) a {
	position: relative;
	top: 3px;
	right: -5px;
}
ul li a:hover{
  transform: scale(1.25);
  -webkit-transform: scale(1.25);
  -moz-transform: scale(1.25);
  -ms-transform: scale(1.25);
  -o-transform: scale(1.25);
  /*为了使放大效果更佳美观  所以我们也可以将鼠标悬停时的阴影（透明度这一块）加点改变*/
  box-shadow: 0 3px 6px rgba(0,0,0,0.25) ;
  -webkit-box-shadow: 0 3px 6px rgba(0,0,0,5);
  -moz-box-shadow: 0 3px 6px rgba(0,0,0,5);
  -o-box-shadow: 0 3px 6px rgba(0,0,0,5);
  -ms-box-shadow: 0 3px 6px rgba(0,0,0,5);
}
.menu3{
  width: 1000px;
  height: 40px;
  background-color: gainsboro;
}

.menu3 li{
  float: left;
  width: 120px;
  height: 40px;
  line-height: 40px;
  text-align: center;
}

.menu3 a{
  display: block;
  color: rgb(233, 35, 35);
  height: 40px;
  width: 120px;
  /* border-right: 1px solid #ccc; */
  border-bottom: 1px solid #808080;
  
}

.menu3 a:hover{
  background-color: #666;
  color: #fff;
  border-bottom: 1px solid red;
}

.menu3 .submenu{
  visibility: hidden;
  width: 120px;
}

.menu3 li:hover .submenu{
  visibility: visible;
  position: relative;
  z-index: 100;
} 

.menu3 ,.submenu li{
  height: 40px;
  line-height: 40px;
}

.menu3 .submenu a{
  background-color: #666;
  color: rgb(91, 231, 241);
  border: 0;
}

.menu3 .submenu a:hover{
  background-color: #333;
}

